Semantic HiFi - an EC-commissioned research project in partnership with Fraunhofer. I'm just going to quote the web site:
In the context of large scale digital music, the goal of the project is to develop a new generation of HIFI systems, offering new functionality for browsing, interacting, rendering, personalizing and editing musical material. This next generation of Hard-disk based HIFI systems will change drastically the relation of home users to music and multimedia content. Users will be able to interact with music up to the point of blurring the traditional limits between playing, performing and remixing. These HIFI systems will be listening stations as much as open instruments.
Technically, with IPv6, every HIFI system will have an IP address and systematic use of metadata extraction and exploitation techniques will allow semantic or thematic browsing in large content catalogues over Web and file sharing systems. Converging with the TV, DVD, Game Station and 5.1 set-ups, HIFI systems will also bring 3D audio real-time navigation in the sound scene.
The main innovations include a deeper access to the audio content and structure, through state-of-the-art semantic musical metadata extraction and exploitation (partially from MPEG-7): temporal segmentation, polyphonic, melodic, and high-level descriptions like genre, etc. Users will be offered innovative possibilities of manipulation, edition, recomposition, organization, sharing and interactivity with the audio material, and true 3D audio rendering and real time remixing of music.
Using music from CDs, consumers will be able to freely exchange metadata information enriching their music and allowing them to listen to remix sessions performed by other users. But with appropriate DRM systems sharing music files is also possible and may even support new profitable music business models for the music industry.
Also involved are 4FO, developers of the Potato System, which allows web sites to receive commission for selling legal music downloads (as used by Dorfdisco, though I haven't tried buying anything yet) and the P2P-Potato-Messenger, for which I can't find a download link but appears to be the closest yet to my ideal P2P payment and distribution model.